What is the speed of a wave with a wavelength of 0.60 m and frequency of 240 Hz

A driver slammed on her brakes and came to a stop with constant acceleration. Measurements on her tires and skid marks on the pa

IRISSAK [1]

Answer:

u = 29.22 m/s

Explanation:

distance (s) = 58.52 m

coefficient of kinetic friction (k) = 0.75

final velocity (v) = 0 m/s

acceleration due to gravity (g) = 9.8 m/s^{2}

How fast was she driving (u)

we can get how fast she was driving by using the formula below

s = ut - $\frac{1}{2}.at^{2}$ ...equation 1

where

s = distance
u = her initial velocity
a = acceleration = $\frac{f}{m} = \frac{kmg}{m} = kg$

k = coefficient of kinetic friction
g = acceleration due to gravity

t = time

from v = u - at (recall that v = 0)

0 = u - at, therefore t = u/a = u/kg

now substituting the required values above into equation 1 we have

s = $\frac{u^{2}}{kg} - \frac{u^{2}}{2kg}$

s = $\frac{u^{2}}{2kg}$

u = $\sqrt{2kgs}$

u = $\sqrt{2 x 0.75 x 9.8 x 58.52}$

u = 29.22 m/s

8 0

2 years ago

3. A model rocket is launched straight upward at 58.8 m/s.

SIZIF [17.4K]

Let us assume that rocket only runs in initial energy and not using its own to flying.

Also , let upward direction is +ve and downward direction is -ve .

Initial velocity , u = 58.8 m/s .

Acceleration due to gravity , $g=-9.8\ m/s^2$ .

Final velocity , v - = 0 m/s .

We know , by equation of motion .

$v^2-u^2=2gh\\\\2gh_{max}=0^2-58.8^2\\\\h_{max}=\dfrac{0^2-58.8^2}{-2\times 9.8}\\\\h_{max}= 176.4\ m$

Hence, this is the required solution .

8 0

3 years ago

The weight of an astronout is 60kg on earth, find the wight of the same object on the planet where the gravitational attraction

Marianna [84]

The astronaut's weight is not 60 kg anywhere, because kg is a unit of mass, not weight.

If the astronaut's mass is 60 kg, then his weight is (60 kg)x(acceleration of gravity).

That's 588 Newtons on Earth, and 58.8 Newtons on a planet with 1/10 Earth's gravity.

The astronaut's mass of 60 kg goes with her, and doesn't depend on where she is.

3 0

3 years ago

An electron has a constant acceleration of +3.3 m/s2. at a certain instant its velocity is +8.6 m/s. what is its velocity (a) 2.

Citrus2011 [14]

Hello!

The velocity function is:

$\mathsf{V = V_0 + at}\\ \\ \mathsf{V = 8.6 +3.3t}$

a) 2.3 s earlier, we can make t = -2.3 s, in relation to our initial time:

$\mathsf{V = 8.6 + 3.3\cdot(-2.3)}\\ \\ \mathsf{V = 8.8-7.59}\\ \\ \boxed{\mathsf{V = 1.21 \ m/s}}$

b) Now we can make t = 2.3 s:

$\mathsf{V = 8.6 + 3.3\cdot2.3}\\ \\ \mathsf{V = 8.6 + 7.59}\\ \\ \boxed{\mathsf{V = 15.59 \ m/s}}$

7 0

3 years ago

If a steel containing 1.88 wt%C is cooled relatively slowly to room temperature, what is the expected weight fraction of pearlit

Oxana [17]

Answer:

The answer is %pearlite = 0.06%

Explanation:

according to the exercise we have that the percentage is 1.88% C, therefore, the percentage of perlite is equal to:

%pearlite = (B*C)/(A*C) = (2-1.88)/(2-0) = 0.06%

The percentage of cementite is equal to:

%cementite = (1.88-0)/(2-0) = 0.94%

4 0

3 years ago